HCID 18653183, compound → HCID 18653187, compound

HRID 2253971Notes

Reaction equation

HRID 2253971 reaction equation
C([O:4][C:5]1[CH:23]=[CH:22][C:8]([CH2:9][C@H:10]2[CH2:15][CH2:14][C:13]3[CH:16]=[C:17]([CH:20]=[O:21])[CH:18]=[CH:19][C:12]=3[O:11]2)=[CH:7][CH:6]=1)(=O)C>CO.O1CCCC1.[OH-].[Na+]>[CH:20]([C:17]1[CH:18]=[CH:19][C:12]2[O:11][C@@H:10]([CH2:9][C:8]3[CH:22]=[CH:23][C:5]([OH:4])=[CH:6][CH:7]=3)[CH2:15][CH2:14][C:13]=2[CH:16]=1)=[O:21]

Participants

5

Reactant 1

HCID 18653183HCID 18653183, compound

Product 1

HCID 18653187HCID 18653187, compoundYield 73.8%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 8028TetrahydrofuranSolventHCID 14798Sodium HydroxideSolvent

Procedure

(R)-(-)-2-(4-Acetoxybenzyl)-3,4-dihydro-6-formyl-2H-benzopyran (15.7 g, 51 mmol) was dissolved in a mixture of methanol (200 ml), tetrahydrofuran (200 ml) and 2M NaOH (200 ml) and stirred at room temperature for 2 hours. The reaction mixture was concentrated in vacuo, diluted with water (100 ml) and acidified with 10% HCl (250 ml). The aqueous solution was extracted with ethyl acetate (2×500 ml) and the combined organics were washed with water (250 ml), brine (250 ml), and dried (MgSO4). The solvent was removed in vacuo and the residue was crystallized from hexanes/ethyl acetate (3:1) to afford 10.1 g of the title compound, mp 134°-135° C.; [α]D -155.2° (c 1.0, MeOH); 1H NMR (300 MHz CDCl3) δ1.6 (m, 1H), 1.9 (m, 1H), 2.8 (m, 3H), 3.0 (dd, 1H), 4.2 (m, 1H), 5.1 (br s, 1H, OH), 6.7 (d, 2H), 6.8 (d, 1H), 7.0 (d, 2H), 7.5 (m, 2H), 9.7 (s, 1H).

Workup

  1. concentrationThe reaction mixture was concentrated in vacuo
  2. additiondiluted with water (100 ml)
  3. extractionThe aqueous solution was extracted with ethyl acetate (2×500 ml)
  4. washthe combined organics were washed with water (250 ml), brine (250 ml)
  5. dry with materialdried (MgSO4)
  6. customThe solvent was removed in vacuo
  7. customthe residue was crystallized from hexanes/ethyl acetate (3:1)

Sources & evidence

ORD record
ord-84a13971052d452ca9df96fc420f86a6
Source dataset
uspto-grants-1993_08
Patent number
US05232945

Reaction notes

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